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A147799 Minimal value of A007947(m(7^n-m)) with m coprime to 7. 4
6, 6, 30, 30, 282, 2262, 17034, 36006, 71070 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The minima are reached for m values given in A147804.

This is related to the abc conjecture, see also A143702, A147801, A147800 (2^n, 3^n, 5^n analogs) and A147298 (general case).

All terms of this sequence are even, so one could also consider A147799/2 = 3, 3, 15, 15, 141, 1131, 8517, 18003, 35535, ... So far these terms are also multiples of 3, but this might be a coincidence.

LINKS

Table of n, a(n) for n=1..9.

PROG

(PARI) A147799(n, p=7)={ local( m=n=p^n ); for( a=1, n\2, a%p|next; m > 2*A007947(a) | next; m > A007947(n-a)*A007947(a) | next; m = A007947(n-a)*A007947(a) ); m }

CROSSREFS

Cf. A007947, A147804 (m values); A143702, A147801, A147800 (analog for 2^n, 3^n, 5^n), A147298 (general case).

Sequence in context: A054436 A055522 A078637 * A071021 A279865 A321528

Adjacent sequences:  A147796 A147797 A147798 * A147800 A147801 A147802

KEYWORD

more,nonn

AUTHOR

M. F. Hasler, Nov 13 2008

STATUS

approved

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Last modified November 14 03:52 EST 2018. Contains 317159 sequences. (Running on oeis4.)